In this year, we conducted three major sub-projects. First, we employed glucose-sensitive sensors coupled with high-speed amperometry to evaluate rapid fluctuations in brain glucose levels following exposure to heroin and other opioid drugs. Second, we conducted a study, in which we examined fluctuations in brain glucose induced by general anesthesia. Third, we examined changes in brain glucose induced by iv injections of glucose and occurring during glucose- and fructose-drinking behavior.